Nixxes just added FSR 3.1 to all recent Sony titles on PC. This update improves quality and temporal stability while boosting frame rates by up to 10%. It also allows you to pair AMDs open-source (works on everything) frame generation with DLSS-based upscaling.
Source: N4G PC AMD FSR 3.1 Frame Gen 15% Faster than DLSS 3.5: Ghost of Tsushima, Horizon Forbidden West